- Category: Helgard's Column
- Published on 04 October 2016
- Hits: 185
The sixth Regional African Water Leakage Summit was held in Midrand in August. The conference opened with keynote speeches by two world leaders on water leakage, namely Ronnie McKenzie, the chairman of the IWA Water Loss Specialists Group: Global Water Losses, and the former chairman Tim Waldron.
Tim Waldron started by saying: “South Africans have unique problems that you do not see anywhere else in the world, but you have wonderful people and extraordinary ways to solve your problems.” Waldron believes that the Khayelitsha Pressure Management System is the best pressure management system in the world and one he continues to promote as ‘best case’ practice in his work around the globe. The Khayelitsha project saves the City of Cape Town 24Mℓ per day, with having recorded a total direct water saving of R59-million in the first two years of operation. In addition to the reduction in water demand, there was an additional saving on the delay of new infrastructure.
A bleak picture was painted by several experts warning that unless water use efficiencies are improved in our municipal systems, we face serious water shortages in future with subsequent damaging impacts on social and economic development. As a water scarce country, we are using water far above our means: an average of 235ℓ per person per day against a world benchmark of 173ℓ a day, according to the ActionAid report Running on empty, published in April 2016.
Water losses are extensive in many parts of the country. Officials from the Department of Water and Sanitation (DWS) — Allestair Wensley, Paul Herbst and Moloko Raletjena — shared the results from non-revenue water (NRW) monitoring by the DWS, as well as some of the results from the first No Drop report. The Western Cape scored the best with a modest 20.2% NRW, with Limpopo at the other end with a massive 50% NRW. The financial implications of these losses are staggering: if the losses could be halved then the country could save R2-billion per year.
Some basic but key lessons learnt from the summit:
- Know and understand the water distribution system by dividing it up into zones for monitoring.
- Instead of building new pipelines or employing tanker trucks, repair the leaks.
- Reduce the pressure. The dramatic effect of lower pressure on existing leaks is often ignored, while technology is available to make a huge difference.
- Repairs need to be undertaken urgently, as the water and financial losses can otherwise be significant — compare a four-hour repair job with a four-day repair job.
- It can make financial sense for a municipality to do plumbing repairs in low-income households. Dumisani Gubuza from Ekurhuleni Metropolitan Municipality presented such an example.
- Intermittent supply is a no-no. This water equivalent to electricity load-shedding — as is now promoted in some municipalities — is counter-productive to the steady hydraulics principle of pressure water supply. Intermittent supply creates vacuums that suck in contamination. Intermittent supply results in non-equitable distribution and fluctuations in pipe pressure that can lead to more pipe breakages, especially in the case of PVC pipes. Ultimately, intermittent supply will lead to even higher water usage, as many cases across the globe have proved.
We have the expertise to assist us, so let’s hope that our municipalities, companies, and institutions work with the experts to the benefit of their organisations and ultimately, to the well-being of all of us.